#include <fstream>
#include <list>

#define NMAX 100001

using namespace std;

int n, m, count;
list<int> graph[NMAX];
int marks[NMAX];

void dfs(int x)
{
	// skip if marked
	if (marks[x])
		return;
	marks[x] = 1;

	// dfs on neighbors
	for (int y : graph[x])
		dfs(y);
}

int main()
{
	// read input
	ifstream fin("dfs.in");
	fin >> n >> m;
	
	for (int i = 0; i < m; i++) {
		int x, y;
		fin >> x >> y;
		graph[x].push_back(y);
		graph[y].push_back(x);
	}
	
	fin.close();

	// dfs
	for (int i = 1; i <= n; i++) {
		if (!marks[i]) {
			count++;
			dfs(i);
		}
	}

	// print output
	ofstream fout("dfs.out");
	fout << count;
	fout.close();

	return 0;
}